Shell construction



Dem 1966 H. H. RUDOLPH ETAL 3,289,585

SHELL CONSTRUCTION Filed April 25, 1965 FIGE INVENTORS, I H HANS HElNRICH RUDOLPH DIETER MENZEL ATTORNEYS.

United States Patent Ofiice 3,289,585 Patented Dec. 6, 1966 3,289,585 SHELL CONSTRUCTION Hans Heinrich Rudolph and Dieter Menzel, Egersdorf uber Nurnberg, Germany, assignors to Dynamit Nobel Aktiengesellschaft, Troisdrof, Germany Filed Apr. 23, 1965, Ser. No. 450,401 Claims priority, application Germany, Apr. 23, 1964, D 44,248 20 Claims. (Cl. ltl24l) The present invention relates to a shell, and more particularly, to a shell for maneuver ammunition having a case of thermoplastic or analogous material and containing an easily decomposable powder-like filling.

It is known to utilize for maneuver ammunition with smallest danger range, shells which are provided within a more or less flexible case made of plastic material with a filling of metal powder or of metal powder blanks whereby the shell Weight is, for the most part, matched to the weight of a corresponding live shell in order that with use in semior fully automatic weapons, the proper functioning thereof is assured Without special measures. In order to prevent danger to persons and also objects which are disposed at some small distance from the muzzle of the firing weapon, these shells should disintegrate or explode on or at least directly after leaving the gun barrel. For this purpose, it has also been proposed already with a flexible shell case to arrange a fixed plug behind the powder-like filling so that this plug under the influence of the propellant gases exerts a corresponding pressure on the metal powder mass and thereby initiates a forcible decomposition or disintegration of the shell.

However, as has been found in practice, with the aforementioned known shells for maneuver ammunition, that is, the so-called decomposing or disintegrating shells, the correctly timed decomposition for disintegration, namely, the decomposition or destruction desired exactly at the instant of leaving the gun mouth, is not assured with sufficient certainty. Rather, it may happen with the prior art constructions that the shell burss or disintegrates already in the barrel, that is, sill prior to leaving the barrel. Inversely, it may also happen with the prior art constructions that such a shell, if it does not burst within the barrel, remains completely intact or non-disintegrated or at least partly still undestroyed or non-disintegrated in front of the barrel muzzle. Both the one as well as the other malfunctioning is of disadvantage and therefore undesirable. In the former case, there exists the danger that the gun barrel is ground out by the filling material driven therethrough at high velocity. In the latter case there exists the danger that undestroyed shell parts possessing a high penetrating energy, fly over a relatively large distance so that the safety required of maneuver ammunition is no longer assured.

The cause for the undesirable behavior of the shell can be traced back essentially to an excessive firing pressure in relation to the rigidity of the shell case and to a corresponding inadequate rotational pressure. Under firing pressure is understood herein that pressure which is exerted by the shell filling on the shell case under the effect of the pressure of the powder gases of the propellant charge on the rear end and by reason of the pressure distribution in the shell filling. Rotational pressure, in contrast thereto, is the pressure which is exerted by the shell filling on the shell case by reason of the rotation of the shell filling owing to the centrifugal force.

As can be readily calculated, the firing pressure is greater than the rotational pressure. The firing pressure which remains effective only as long as the shell is still in the barrel, has its maximum value directly after setting the shell into motion simultaneous with the maximum of the pressure of the propellant gases. The rotational pressure is effective as soon as the shell is set into rotation by the rifting. The maximum value of the rotational pressure is reached at the mouth of the gun. However, in contrast to the firing pressure, the rotational pressure remains still effective also outside of the barrel.

During the passage of the shell through the barrel, the rotational pressure is absorbed in that the shell case abuts against the barrel walls. However, there exists the tendency by reason of the higher firing pressure that the tip of the shell case is deformed already in the barrel and thereby is decomposed or burst so that also the shell filling is released whereby, however, the aforementioned disadvantage results that the particles of the powder-like shell filling driven through the barrel at high velocity slide along the inner wall of the barrel and grind out the barrel cross section by reason of the occurring friction. Insofar as such a premature destruction or disintegration of the shell case does not occur under the effect of the firing pressure, it may happen, on the other hand, that the shell is not destroyed at all or only insufficiently at or directly after leaving the barrel. This finds its cause, inter alia, in the fact that the rotational acceleration of the shell case caused during firing by the rifiing of the grooves of the barrel is not transmitted completely from the smooth inner surfaces of the case to the powder-like shell filling. A slippage results between the case and the filling so that the rotational pressure exerted by the latter on the shell case does not reach the desired value necessary for the decomposition or disintegration of the shell.

The aim of the present invention is to eliminate the aforementioned disadvantages, that is, to so construct the shell case that, on the one hand, it is not damaged or deformed by the strong firing pressure but, on the other, is decomposed by the slight rotational pressure (centrifugal force) in front of the mouth into small parts incapable of flight. It is therefore proposed in accordance with the present invention for a shell for maneuver ammunition With a case of thermoplastic material and an easily disintegrating powder-like filling to reinforce the case at least at the foremost part forming the shell tip at least on the inside thereof with ribs extending in the longitudinal direction and distributed over the circumference.

The effect of this measure can be further enhanced if, according to a further proposal of the present invention, weakened grooves are provided between the reinforcing ribs or if the intermediate spaces between adjacent reinforcing ribs are enlarged into weakened grooves or zones Within Which the material of the case is particularly easily stressed by the rotational pressure above its tensile strength so that the rotational pressure effects in these areas of the case an exploding. However, it is also effective in the same sense if the part of the case adjoining the shell tip is provided on the inside thereof with a grooving extending in the longitudinal direction. This is so as such grooving effects that the rotational acceleration of the casing during firing is transmitted to in increased extent to the shell filling so that the filling, at the arrival of the shell at the barrel muzzle, rotates with a velocity essentially corresponding to the angular momentum of the shell or the rotational velocity of the case and therewith exerts an increased rotational pressure on the case.

It is proposed as a further appropriate development of the present invention to construct the case on the inside thereof at the transition from the tip to the rearward, essentially cylindrical part with one or several step-shaped offsets extending over the entire circumference so that the interior space of the case is enlarged in the rearward direction within this section in a step-like offset manner. It is achieved and also attained by this measure that the thrust which is exerted by the filling material of the shell on the case by reason of the pressure of the propellant gases on the rear shell end, is

absorbed to a considerable extent by these offsets and the sensitive shell tip is correspondingly relieved to a considerable part from the firing pressure, which can be additionally favored in that a partition bottom is arranged on one of the offsets or steps, preferably on the rearmost offset or step, which extends over the entire internal case cross section.

According to a further proposal of the present invention, provision may be made to line the tip of the shell case with a jacket-like insert of a material having high stretch characteristics, especially of thermoplastic material. One aims and also achieves by this provision, with whose application the case may, of course, be dimensioned correspondingly weaker or thinner, that also with an explosion of the case within the barrel of the gun, a contact between filling and barrel wall is avoided with certainty.

Accordingly, it is an object of the present invention to provide a shell for maneuver ammunition which obviates by simple means the aforementioned drawbacks and shortcomings encountered with the prior art constructions.

It is another object of the present invention to provide a shell for maneuver ammunition which assures a properly and accurately timed decomposition or explosion of the shell with a certainty unattainable heretofore.

Another object of the present invention resides in the provision of a shell which is so constructed and arranged that its disintegration and destruction, exactly as it leaves the barrel mouth, is assured with great accuracy.

Still a further object of the present invention resides in the provision of a shell which is simple in construction and readily adaptable to inexpensive mass production techniques, yet is completely safe in use for maneuver ammunition and assures a minimum danger of wear of the barrel walls even in case of premature explosion while still within the barrel of the gun.

Another object of the present invention resides in a shell made of plastic material and intended for maneuver purposes in which the rotational pressure necessaryfor appropriate destruction is assured while the shell case is so constructed that it is neither damaged nor deformed by the high firing pressure.

A further object of the present invention resides in the provision of a maneuver shell in which the shell tip is relieved to a considerable extent from the firing pressure caused by the propellant gases.

These and further objects, features, and advantages of the present invention will become more obvious from the following description when taken in connection with the accompanying drawing which shows, for purposes of illustration only, several embodiments in accordance with the present invention, and wherein:

FIGURE 1 is an axial longitudinal cros-sectional view through a shell case with a tip reinforced by ribs in accordance with the present invention,

FIGURE la is a cross-sectional view taken along line A-A of FIGURE 1,

FIGURE 2 is an axial longitudinal cross-sectional through a modified embodiment of the shell case in accordance with the present invention, similar to FIGURE 1 but provided with an additional grooving along the inner surfaces of the rear section thereof,

FIGURE 2a is a cross-sectional view taken along line B-B of FIGURE 2,

FIGURE 3 is an axial longitudinal cross-sectional view through a still further modified embodiment of a shell case in accordance with the present invention provided with a rib reinforcement and with a transition between tip and cylindrical section offset in a step-shaped manner, and

FIGURE 4 is a longitudinal axial cross-sectional view through still another modified embodiment of a shell in accordance with the present invention provided with a rib-reinforced, jacket-like liner of the tip thereof.

Referring now to the drawing wherein like reference numerals are used throughout the various views to designate like parts, and more particularly to FIGURES 1 and 1a, reference numeral 1 designates therein the shell case constructed with a cylindrical rear section 3 which is provided within the area of the ogival-shaped tip 2 on the inside with six rib-like reinforcements 4 so that the tip 2 has an internal cross section similar to the shape of a star. In addition to a reinforcement of the case tip 2 against the firing pressure also an improved transmission of the rotational velocity of the case 1 to the powder-like filling (not shown) is achieved with the reinforcements 4 which, in turn, has as a consequence that the filling exerts on the case 1 an increased rotational pressure so that the latter, when it reaches its maximum value at the barrel mouth, causes the case 1 to burst with great certainty and correspondingly effects a completely satisfactory destruction and decomposition of the shell. This course is additionally favored in that weakened zones 5 are created between the individual reinforcements 4, whose presence and construction has as a consequence that the stretching of the material under the effect of the rotational pressure is localized to these areas so that correspondingly also the tensile strength of the material is exceeded at first within these areas and consequently the bursting of the case starts in these accurately defined areas.

The shape, dimensions, and number of the reinforcements 4 are to be understood, of course, only as illustrative. For example, provision may also be made to extend the reinforcements 4 over a more or less large area of the cylindrical part 3. It is, however, also possible to arrange the ribs 4 on the outside of the case 1.

According to FIGURES 2 and 2a, the tip 2 of the case 1 is again constructed with the reinforcements 4 of FIG- URE 1 whereas the adjoining cylindrical section 3 is provided with a grooving 6 extending in the longitudinal direction. Since the outer diameter of the cylindrical section 3 of the case 1 is matched very accurately to the inner diameter of the barrel of the gun, hence this part of the case 1 during passage of the shell through the barrel is well supported by the barrel wall against the effect of the rotational pressure, the wall thickness of the cylindrical section 3 can be kept relatively small, that is, the grooving can be constructed in the form of a large number of relatively deep groove-like recesses or indentations whereby there is achieved, on the one hand, a favorable transmission of the rotational velocity of the case 1 to the filling (not shown) and, on the other, an advantageous influencing of the intended destruction of the shell by the rotational pressure when leaving the barrel.

The case 1 illustrated in FIGURE 3 is provided at the tip 2 with slightly differently constructed reinforcing ribs 4 of which only two are shown-and more particularly in cross sectionwhereby the depth of the ribs 4 as indicated by the dash lines 8 passing over into the cylindrical surface 7. Within the transition from the tip 2 to the rear cylindrical section 3 which, in this case, may also be provided with a grooving, the wall thickness of the case 1 is offset in a step-shaped manner. The partition bottom 10 is arranged on the thus-formed annular surface 9 which absorbs the pressure exerted by the propellant gases on the filling (not shown) of the cylindrical section 3 and introduces the same by way of the annular surface 9 into the forward part 2 of the case 1 whereby the filling of the shell tip 2 is essentially relieved of the gas pressure of the propellant charge, hence the filling of the shell tip 2 thus cannot exert any longer any significant pressure stemming from the propellant gases on the sensitive tip 2 of the case 1.

In the embodiment according to FIGURE 4, the tip 2 of the case 1 is lined with a liner 11 which in its turn is provided with the reinforcing ribs 4 of which one is illustrated in cross section for claritys sake. Of course, the ribs 4 could also be formed into the tip 2 and the liner 11 could be constructed with a uniform wall thickness and having a shape corresponding in its interior dimensions to the rib-reinforced tip 2. In order to assure in the illustrated case the completely satisfactory transmission of the rotational speed of the case caused by the rifling to the liner 11 made of material with high stretch characteristics, especially of thermoplastic material, and by way of the liner 11 to the filling (not shown), the liner 11 may, if necessary, be glued, bonded, or cemented into the tip 2 or the inner surfaces of the tip 2 as well as the outer surfaces of the liner 11 may be constructed more or less rough. Of course, also in this case, a partition bottom could be provided at the rear end of the liner whereby the construction of step-shaped offset would be obviated since such an offset results automatically from the rear end face of the liner. Furthermore, also in this as well as all other embodiments,-ribs4 may be provided along the outside of the tip 2 and/ or a grooving may be provided within the cylindrical section 3.

While we have shown and described several embodiments in accordance with the present invention, it is understood that the same is not limited thereto but is susceptible of numerous changes and modifications as known to a person skilled in the art; and we therefore do not wish to be limited to the details shown and described herein, but intend to cover all such changes and modifications as are encompassed by the scope of the appended claims.

We claim:

1. A shell for maneuver ammunition, comprising case means, an easily disintegrating powder-like filling means within said case means, the forward part of said case means forming the shell tip, the internal diamete of said shell tip being substantially less than the internal diameter of said rearward section substantially at their junction, a generally radially inwardly extending and rearwardly facing substantially longitudinal extending reinforcing rib means reinforcing said case means at least in the area of said shell tip, said rib means being distributed over the circumference and being provided at least one the inside of said shell tip,

and at least one step-shaped offset means extending over the entire circumference for enlarging the interior space of the case means at the transition from said shell tip to the substantially cylindrical rearward section of said case means, and said offset means absorbing to a substantial extent the thmst exerted by said filling means because of the propellant gas pressure on the rear of the shell during firing.

2. The device of claim 1, wherein said rearward section has a substantially uniform relatively small wall thickness and said shell tip has a relatively larger wall thickness.

3. A shell for maneuver ammunition, comprising case means, an easily disintegrating powder-like filling means within said case means, the forward part of said case means forming the shell tip, and substantially longitudinally extending reinforcing rib means reinforcing said case means at least in the area of said shell tip, said rib means being distributed over the circumference and being provided at least on the inside of said shell tip,

and at least one step-shaped offset means extending over the entire circumference for enlarging the interior space of the case means at the transition from said shell tip to the substantially cylindrical rearward section of said case means,

and partition wall means extending over the entire interior case cross section and arranged on said offset means.

4. The device of claim 3, wherein said case is constructed of a relatively low stretch capacity onganic plastic material, and including liner means covering substantially the entire inside surface of said shell tip of a material having a relatively high stretch capacity, and said liner means preventing said filling means from contacting the barrel Wall when said shell tip ruptures within the barrel during firing.

5. A shell for maneuver ammunition, comprising case means, an easily disintegrating, powder-like filling means within said case means, the forward part of said case means forming the shell tip, and substantially longitudinally extending reinforcing rib means reinforcing said case means at least in the area of said shell tip, said rib means being distributed over the circumference and being provided at least on the inside of said shell tip,

a plurality of step-shaped offset means extending over the entire circumference and enlarging the interior space of the case means at the transition from the shell tip to the substantially cylindrical rearward section of said case means,

and partition wall means extending over the entire interior case cross section and arranged on the rearmost offset means. 7 r W 6. The device of claim 5, wherein said case is constructed of a relatively low stretch capacity organic plastic material, and including liner means covering substantially the entire inside surface of said shell tip of a material having a relatively high stretch capacity, and said liner means preventing said filling means from contacting the barrel wall when said shell tip ruptures within the barrel during firing,

7. A shell for maneuver ammunition, comprising case means, an easily disintegrating powder-like filling means within said case means, the forward part of said case means forming the shell tip, and substantially longitudinally extending reinforcing rib means reinforcing said case means at least within the area of said shell tip, said rib means being distributed over the circumference of the shell tip,

said shell tip including a relatively low stretch capacity outside layer, liner means covering substantially the entire inside surface of said shell tip outside layer of a material having a relatively high stretch capacity, and said liner means preventing said filling means from contacting the barrel wall when said shell tip ruptures within the barrel during firing.

8. A shell for maneuver ammunition according to claim 7, wherein said reinforcing rib means is provided at said liner means.

9. In a shell for maneuver ammunition having a case of thermoplastic-like material and an easily destructible powdef-like filling within said case, with the forward part of said case forming the shell tip, said case means having a substantially cylindrical rearward section,

the improvement essentially consisting of reinforcing rib means reinforcing said case means at least within the area of said shell tip, the internal diameter of said shell tip being substantially less than the internal diameter of said rearward section substantially at their junction,

and means in the form of generally radially inwardly extending and rearwardly facing annular offsets in said case at the transition from the shell tip to the rearward case section for relieving the shell tip of firing pressure caused by the thrust exerted by said filling because of the propellant gas pressure on the rear of the shell during firing.

10. In a shell for maneuver ammunition according to claim 9, wherein said reinforcing rib means extending substantially in the longitudinal direction and being provided at least on the inside of said shell tip.

11. A shell for maneuver ammunition, comprising case means, an easily disintegrating powder-like filling means within said case means, the forward part of said case means forming the shell tip, and substantially longitudinally extending reinforcing rib means reinforcing said case means at least in the area of said shell tip, said rib means being distributed over the circumference and being provided at least on the inside of said shell tip, and means in said case means effectively forming weakened Zones within the spaces between said rib means,

the section of said case means adjoining said shell tip being provided on the inside thereof with substantially longitudinally extending groove means,

and at least one step-shaped offset means extending over the entire circumference for enlarging the interior space of the case means at the transition from said shell tip to the substantially cylindrical rearward section of said case means,

and partition wall means extending over the entire interior case cross section and arranged on said offset means.

12. The device of claim 11, wherein said case is constructed of a relatively low stretch capacity organic plastic material, and including liner means covering substantially the entire inside surface of said shell tip of a material having a relatively high stretch capacity, and said liner means preventing said filling means from contacting the barrel wall when said shell tip ruptures Within the barrel during firing.

13. A shell for maneuver ammunition, comprising case means of thermoplastic-like material, an easily disintegrating, powder-like filling means within said case means, the forward part of said case means forming the shell tip, and substantially longitudinally extending reinforcing rib means reinforcing said case means at least in the area of said shell tip, said rib means being distributed over the circumference and being provided at least on the inside of said shell tip, and means in said case means forming weakened zones within the spaces between said rib means,

the section of said case means adjoining said shell tip being provided on the inside thereof with longitudinally extending groove means,

a plurality of step-shaped offset means extending over the entire circumference and enlarging the interior space of the case means at the transition from the shell tip to the substantially cylindrical rearward section of said case means,

and partition wall means extending over the entire interior case cross section and arranged on the rearmost offset means.

14. A shell for maneuver ammunition, comprising case means of thermoplastic-like material, an easily disintegrating, powder-like filling means within said case means, the forward part of said case means forming the shell tip, and substantiallly longitudinally extending reinforcing rib means reinforcing said case means at least in the area of said shell tip, said rib means being distributed over the circumference and being provided at least on the inside of said shell tip, and means in said case means forming weakened zones within the spaces between said rib means,

the section of said case means adjoining said shell tip being provided on the inside thereof with longitudinally extending groove means,

a plurality of step-shaped offset means extending over the entire circumference and enlarging the interior space of the case means at the transition from the shell tip to the substantially cylindrical rearward section of said case means,

and partition wall means extending over the entire interior case cross section and arranged on the rearmost offset means,

said shell tip being lined with a liner of a material having high stretch capacity, and said reinforcing rib means being provided on said liner.

15. A shell for maneuver ammunition, comprising: a case of relatively easily rupturable material; an easily disintegrating powder-like filling means within said case for duplicating the weight characteristics of a conventional corresponding shell; the forward part of said case forming a shell tip of generally conical configuration; said case having a substantially cylindrical rearward section; a partition wall means extending over substantially the entire interior cross-section of said case essentially at the juncture between said cylindrical rearward section and said shell tip for absorbing the thrust exerted by said filling because of the propellant gas pressure in the rear of the shell during firing.

16. The device of claim 15, wherein the thickness of said shell tip is substantially greater than the thickness of said rearward section, and said case includes a generally radially extending step shaped offset extending over the entire circumference for enlarging the interior space of the case at the juncture between said shell tip and said substantially cylindrical rearward section forming a forward abutment for said partition means.

17. The device of claim 16, wherein said case is homogeneously constructed of an organic plastic material.

18. The device of claim 16, wherein said case is constructed of a relatively low stretch capacity organic plastic material, and liner means for covering substantially the entire inside surface of said shell tip of a material having a relatively high stretch capacity, and said liner means preventing said filling from contacting the barrel wall when said shell tip ruptures within the barrel during firing.

19. The device of claim 15, wherein said case is homogeneously constructed of an organic plastic material.

20. The device of claim 15, wherein said case is constructed of a relatively low stretch capacity organic plastic material, and liner means for covering substantially the entire inside surface of said shell tip of a material having a relatively high stretch capacity, and said liner means preventing said filling from contacting the barrel wall when said shell tip ruptures within the barrel during firing.

References Cited by the Examiner UNITED STATES PATENTS 7/1961 Ferguson l0241 X 2/1965 Jungermann et al. 10241 X 

1. A SHELL FOR MANEUVER AMMUNITION, COMPRISING CASE MEANS, AN EASILY DISINTEGRATING POWDER-LIKE FILLING MEANS WITHIN SAID CASE MEANS, THE FORWARD PART OF SAID CASE MEANS FORMING THE SHELL TIP, THE INTERNAL DIAMETER OF SAID SHELL TIP BEING SUBSTANTIALLY LESS THAN THE INTERNAL DIAMETER OF SAID REARWARD SECTION SUBSTANTIALLY AT THEIR JUNCTION, A GENERALLY RADIALLY INWARDLY EXTENDING AND REARWARDLY FACING SUBSTANTIALLY LONGITUDINAL EXTENDING REINFORCING RIB MEANS REINFORCING SAID CASE MEANS AT LEAST IN THE AREA OF SAID SHELL TIP, SAID RIB MEANS BEING DISTRIBUTED OVER THE CIRCUMFERENCE AND BEING PROVIDED AT LEAST ON THE INSIDE OF SAID SHELL TIP, AND AT LEAST ONE STEP-SHAPED OFFSET MEANS EXTENDING OVER THE ENTIRE CIRCUMFERENCE FOR ENLARGING THE INTERIOR SPACE OF THE CASE MEANS AT THE TRANSITION FROM SAID SHELL TIP TO THE SUBSTANTIALLY CYLINDRICAL REARWARD SECTION OF SAID CASE MEANS, AND SAID OFFSET MEANS ABSORBING TO A SUBSTANTIAL EXTENT THE THRUST EXERTED BY SAID FILLING MEANS BECAUSE OF THE PROPELLANT GAS PRESSURE ON THE REAR OF THE SHELL DURING FIRING. 